Plastic Bulkhead Light - Earth Wire

[maverickone]

Had to start a new thread just to ask one final question guys as the other got closed.

The plastic light fitting as a square in square symbol as described in the earlier thread. There is no earth connection so I have added a piece of sleeve to the wire and connected it to a plastic block and parked it as advised.

Just to double check I have done the correct thing on the other end of the cable. It goes into a metal clad fused switch which does have an earth connection on the casing but I have reasoned I should not connect the earth wire to this as its not connected at the light fitting.

I have added a piece of sleeve at this end also and again connected it to a plastic block and parked it. have I done it correctly? If so that's one shed finished, and a huge thank you to all that advised me along the way.

 

[rsgaz]

have I done it correctly?

No, you should connect it to the fused switch faceplate's earth terminal.

And, as it's a metal clad back box, it'd be a good idea to have a short earth flylead going from the faceplate earth terminal to the back box's earth terminal. It's gets earthed when you screw the front on, and may already be earthed depending on how you have coupled this box to the socket's box, but extra redundancy can't hurt.

 

[maverickone]

No, you should connect it to the fused switch faceplate's earth terminal.

And, as it's a metal clad back box, it'd be a good idea to have a short earth flylead going from the faceplate earth terminal to the back box's earth terminal. It's gets earthed when you screw the front on, and may already be earthed depending on how you have coupled this box to the socket's box, but extra redundancy can't hurt.

Thank you, I have got the short earth wire from the faceplate to the back box earth, and I will now connect the earth from the light to the faceplate. Is the reason for this purely incase the light fitting should get replaced in the future with one that has an earth terminal?

 

[EFLImpudence]

Is the reason for this purely incase the light fitting should get replaced in the future with one that has an earth terminal?

It is just that - a stupid requirement. It has NOTHING to do with any electrical consideration.

It could be argued that having a CPC (which could become live in the event of a fault elsewhere) is undesirable inside a Class 2 appliance.

 

[ban-all-sheds]

It could also be argued that having a functioning earth core in a cable is desirable.

 

[EFLImpudence]

It could, but it isn't - in the requirement.

 

[ban-all-sheds]

Nor is it in the requirement to not have one safely terminated inside a Class II item.

 

[EFLImpudence]

It wouldn't be, would it?

The requirement does not relate to the Class 2 item, merely the fixed wiring.

 

[ban-all-sheds]

So is this a fair summary of your position:

1. Even though there is no requirement for it not to be there it can be argued that it is undesirable
2. Because there is no requirement for one to be in the cable it cannot be argued that it is desirable.

?

 

[EFLImpudence]

You seem to be having trouble reading lately.

In your first example, I agreed with you but pointed out that that was not the reason for the requirement, and

in your second, I pointed out that what you were arguing was not part of the relevant requirement.


How you wish to interpret these things is up to you.

 

[securespark]

The regs do say that they are a minimum and there is nothing to say you cannot exceed the requirements.

 

[plugwash]

It is just that - a stupid requirement.

Not really stupid. Since we moved from rubber to PVC, Electrical installations last practically forever, light fittings often don't. This is going to become even more the case as we move from incandescents and flourescents with standard bulbs/tubes/starters to LED fittings where the manufactuer doesn't support replacement of the LEDs or driver. Thinking that all such fittings will be replaced by qualified electrians who will test that the earth wire is actually connected to earth is wishful thinking.